Search

INTRODUCTION: There has been an increase in the interest and availability of products asserting to contain cannabidiol (CBD). OBJECTIVE: To describe demographic and clinical patterns in cases involving CBD exposures documented by the America’s Poison Centers (AAPCC). METHODS: We extracted human exposure cases involving CBD from the U.S. National Poison Data System between July 2014 and June 2021. We described monthly case counts and data on demographics, exposure reason, clinical effects, medical outcomes, and co-exposures, overall and by U.S. Food and Drug Administration (FDA) approval status. RESULTS: We identified 6,496 cases, of these, 85.2% involved exposures to non-FDA approved CBD. The monthly number of cases peaked at 336 in March 2021. Cases often occurred in children ages 2–12 years (36.2%). Although in this age group unintentional exposures represented most cases (94.1%), we identified therapeutic errors (3.9%), intentional use (3.0%), and adverse reactions (1.6%) in cases involving exposures to non-FDA approved CBD. Among the 5,248 (80.8%) cases involving exposure to a single product, we identified 44 major medical outcomes, all related to exposures to non-FDA approved CBD. The most frequent clinical effects included neurological, cardiac, and gastrointestinal effects. Among the 1,248 (19.2%) involving exposure to more than one product, the most frequent co-exposures included stimulants and street drugs, sedatives-hypnotics, antipsychotics, and analgesics. CONCLUSIONS: This case series identified an increasing trend in CBD exposure cases managed by AAPCC. It showed serious medical outcomes in temporal association with exposure to non-FDA approved CBD products. Our findings also suggest both unintentional and intentional use of non-FDA approved CBD in children. Consumers should keep these products out of reach of children and exercise caution when purchasing and using non-FDA approved CBD products.

There is growing concern that multiple sclerosis (MS) patients on certain therapies may be at higher risk for severe coronavirus disease 2019 (COVID-19). We conducted a systematic literature review to examine the available data on U.S. therapies approved to treat MS and the risk of SARS-CoV-2 infection or severe COVID-19 outcomes. We conducted searches in PubMed, Embase, and the WHO COVID-19 database through May 2, 2021, and retrieved articles describing clinical data on therapies approved to treat MS and the risk of infection with SARS-CoV-2 or the effects of such therapies on clinical outcomes of COVID-19. The literature search identified a total of 411 articles: 97 in PubMed, 227 in Embase, and 87 in the WHO database. After excluding duplicates and screening, we identified 15 articles of interest. We identified an additional article through a broader secondary weekly search in PubMed. Thus, ultimately, we reviewed 16 observational studies. Available data, which suggest that MS patients treated with anti-CD20 monoclonal antibodies may be at increased risk for severe COVID-19, are subject to relevant limitations. Generally, studies did not identify increased risk for COVID-19 worsening with other therapies approved to treat MS. Based on observational data, biological plausibility, novelty of the drug-event association, and public health implications in a subpopulation with potential impaired response to the COVID-19 vaccines, this safety signal merits further monitoring. Supplementary Information The online version contains supplementary material available at 10.1007/s10072-021-05846-3.

Background The Vaccine Safety Datalink (VSD) identified a statistical signal for an increased risk of Guillain-Barré syndrome (GBS) in days 1–42 after 2018–2019 high-dose influenza vaccine (IIV3-HD) administration. We evaluated the signal using Medicare. Methods We conducted early- and end-of-season claims-based self-controlled risk interval analyses among Medicare beneficiaries ages ≥65 years, using days 8–21 and 1–42 postvaccination as risk windows and days 43–84 as control window. The VSD conducted chart-confirmed analyses. Results Among 7 453 690 IIV3-HD vaccinations, we did not detect a statistically significant increased GBS risk for either the 8- to 21-day (odds ratio [OR], 1.85; 95% confidence interval [CI], 0.99–3.44) or 1- to 42-day (OR, 1.31; 95% CI, 0.78–2.18) risk windows. The findings from the end-of-season analyses were fully consistent with the early-season analyses for both the 8- to 21-day (OR, 1.64; 95% CI, 0.92–2.91) and 1- to 42-day (OR, 1.12; 95% CI, 0.70–1.79) risk windows. The VSD’s chart-confirmed analysis, involving 646 996 IIV3-HD vaccinations, with 1 case each in the risk and control windows, yielded a relative risk of 1.00 (95% CI, 0.06–15.99). Conclusions The Medicare analyses did not exclude an association between IIV3-HD and GBS, but it determined that, if such a risk existed, it was similar in magnitude to prior seasons. Chart-confirmed VSD results did not confirm an increased risk of GBS.

BACKGROUND: Since the last review of vaccine safety surveillance data for erythema multiforme (EM), Stevens Johnson syndrome (SJS), SJS/TEN, and toxic epidermal necrolysis (TEN) (EM/SJS/TEN), over 37 new vaccines have been introduced in the United States. We sought to describe reported EM/SJS/TEN after vaccines during 1999–2017. METHODS: We identified U.S. reports of EM/SJS/TEN received by the Vaccine Adverse Event Reporting System (VAERS) during 1999–2017. We stratified analysis by condition (EM, SJS, or TEN), and analyzed reports by serious or non-serious status, sex, age group, time from vaccination to symptom onset, exposure to known causes of EM/SJS/TEN, and vaccines administered. We used Empirical Bayesian data mining to detect vaccine-AE pairs reported more frequently than expected. RESULTS: Of 466,027 reports to VAERS during 1999–2017, we identified 984 reports of EM, 89 reports of SJS, 6 reports of SJS/TEN, and 7 reports of TEN. Few reports of EM (9%), and most reports of SJS (52%), SJS/TEN (100%), and TEN (100%) were serious. Overall, 55% of reports described males, 48% described children aged < 4 years; 58% of EM/SJS/TEN occurred ≤ 7 days after vaccination. Few reports (≤5%) described exposure to known causes of EM/SJS/TEN. Overall, childhood vaccines (e.g., combined measles, mumps, and rubella vaccine) were most commonly reported. We identified 6 deaths; 4 were exposed to medications associated with EM/SJS/TEN. EM after smallpox vaccine was reported disproportionately among people aged 19–49 years. CONCLUSIONS: EM/SJS/TEN were rarely reported after vaccination; data mining identified a known association between EM and smallpox vaccine.

Sipuleucel-T, an autologous active cellular immunotherapy, is indicated for the treatment of asymptomatic or minimally symptomatic castration-resistant prostate cancer. The U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) received a report of pruritus without rash following the second dose of sipuleucel-T in a patient who had otherwise not started any new medications concurrent with the first and second doses of sipuleucel-T. No further sipuleucel-T was administered, but symptoms persisted for at least 6 weeks despite treatment with several medications aimed at symptomatic relief of pruritus. Rash is the only dermatologic adverse event included in the sipuleucel-T U.S. package insert. A search of the FAERS database yielded seven additional U.S. reports of pruritus and sipuleucel-T identified as the primary suspect medication; two of these occurred prior to the administration of sipuleucel-T (following leukapheresis). In data mining analyses, pruritus following sipuleucel-T was not reported more frequently than expected when compared to all other adverse event-drug/biologic combinations in FAERS. Thus, pruritus following sipuleucel-T administration was rarely, but not disproportionately, reported to FAERS. Although we cannot exclude the possibility that diabetes, malignancy, or other conditions may have contributed to pruritus in our index patient, in view of the timing of sipuleucel-T therapy and onset of symptoms, a drug/biologic-related reaction is plausible. In the appropriate clinical scenario, sipuleucel-T (or its components) should not be overlooked as a potential etiological agent in pruritus.

BACKGROUND: Bexsero(®) (GlaxoSmithKline) is a four-component Neisseria meningitidis serogroup B vaccine (MenB-4C). It was licensed in the United States in 2015 for use among individuals ages 10–25 years. We aimed to assess the post-licensure safety profile of MenB-4C by examining reports received in the Vaccine Adverse Event Reporting System (VAERS). METHODS: VAERS is a national passive surveillance system for adverse events (AEs) following immunization that uses the Medical Dictionary for Regulatory Activities to code reported AEs and the Code of Federal Regulations to classify reports by seriousness. In this case series, we analyzed U.S. reports involving MenB-4C received between January 23, 2015 through December 31, 2018. We used Empirical Bayesian data mining to identify MenB-4C/AE combinations reported at least twice as often as expected. RESULTS: VAERS received 1,867 reports following MenB-4C administration, representing 332 reports per million doses distributed. Most reports were for females (59%), with a median age of 17 years (interquartile range: 16–18 years); 40% of reports described simultaneous administration of other vaccines. The majority of reports were classified as non-serious (96%). The most commonly reported AEs were injection site pain (22%), pyrexia (16%), and headache (16%). Data mining identified disproportionate reporting for “injected limb mobility decreased” secondary to injection site reactions, including extensive swelling of the vaccinated limb and injection site pain. CONCLUSIONS: Analysis of passive surveillance data from over 5.6 million doses of MenB-4C distributed in the United States did not reveal new safety concerns. The large majority of reports were classified as non-serious and the reported AEs were generally consistent with the safety experience described in clinical studies and the product’s package insert. While our results are reassuring, continued post-marketing surveillance is warranted.

Background Guillain-Barre syndrome (GBS) is a serious acute demyelinating disease, an increased risk of which was found after the 1976 swine flu vaccinations. The U.S. Food and Drug Administration, in collaboration with the Centers for Medicare & Medicaid Services, has been conducting active surveillance for GBS after influenza vaccinations of Medicare Fee-For-Service beneficiaries since 2009. Methods We conducted active surveillance for GBS claims in the 2015–2016 and 2016–2017 influenza seasons using the Updating Sequential Probability Ratio Test (USPRT) to monitor for signals of GBS risk. We performed self-controlled risk interval (SCRI) analyses at the end of both seasons, including chart confirmation in the 2015–2016 season, to estimate the odds ratio of GBS risk. We used 1–42 and 8–21 days post-vaccination as primary and secondary risk windows, respectively, and 43–84 days post-vaccination as the control window. Results Over 13 million beneficiaries were vaccinated in each season. USPRT found a low magnitude signal for GBS in both seasons. SCRI analyses did not find excess GBS risk following any influenza vaccine for days 1–42 post-vaccination in either season. In the 2015–2016 season, for the 8–21 day window, our chart-confirmation showed an attributable GBS risk of 0.87 (95% CI: 0.16, 1.49) and 1.68 (95% CI: 0.69, 2.41) cases per million vaccinees after all seasonal and high dose (HD) vaccines, respectively, an elevated GBS risk for beneficiaries aged ≥75 years following all seasonal vaccines (OR: 2.25; 95% CI: 1.15, 4.39) and HD vaccine (OR: 3.67, 95% CI: 1.52, 8.85), and an elevated GBS risk for males who received seasonal vaccines (OR: 2.18; 95% CI: 1.15, 4.15) and HD vaccine (OR: 3.33; 95% CI: 1.35, 8.20). The finding of elevated GBS risk with advancing age and in males is consistent with literature; however, a distinction between HD and SD was a new finding. In the 2016–17 season, for the 8–21 day window, attributed cases showed an attributable GBS risk of 0.87 (95% CI: 0.03, 1.61) and 1.11 (95% CI: 0.00, 2.01) cases per million vaccinees after all seasonal and HD vaccines, respectively. We found no excess GBS risk for standard dose vaccines in the 8–21 day window in either season. Conclusions Our primary analysis finding of no excess GBS risk during both seasons was reassuring. The slightly elevated GBS risk, although in the expected range, in the 8–21 day window after all seasonal and high dose vaccines, but not after standard dose vaccines is hypothesis-generating because the difference may be due to vaccine factors such as antigen amount or strains in various seasons or due to host factors.

ImportanceThe incidence of arterial thromboembolism and venous thromboembolism in persons with COVID-19 remains unclear.ObjectiveTo measure the 90-day risk of arterial thromboembolism and venous thromboembolism in patients hospitalized with COVID-19 before or during COVID-19 vaccine availability vs patients hospitalized with influenza.Design, Setting, and ParticipantsRetrospective cohort study of 41 443 patients hospitalized with COVID-19 before vaccine availability (April-November 2020), 44 194 patients hospitalized with COVID-19 during vaccine availability (December 2020-May 2021), and 8269 patients hospitalized with influenza (October 2018-April 2019) in the US Food and Drug Administration Sentinel System (data from 2 national health insurers and 4 regional integrated health systems).ExposuresCOVID-19 or influenza (identified by hospital diagnosis or nucleic acid test).Main Outcomes and MeasuresHospital diagnosis of arterial thromboembolism (acute myocardial infarction or ischemic stroke) and venous thromboembolism (deep vein thrombosis or pulmonary embolism) within 90 days. Outcomes were ascertained through July 2019 for patients with influenza and through August 2021 for patients with COVID-19. Propensity scores with fine stratification were developed to account for differences between the influenza and COVID-19 cohorts. Weighted Cox regression was used to estimate the adjusted hazard ratios (HRs) for outcomes during each COVID-19 vaccine availability period vs the influenza period.ResultsA total of 85 637 patients with COVID-19 (mean age, 72 [SD, 13.0] years; 50.5% were male) and 8269 with influenza (mean age, 72 [SD, 13.3] years; 45.0% were male) were included. The 90-day absolute risk of arterial thromboembolism was 14.4% (95% CI, 13.6%-15.2%) in patients with influenza vs 15.8% (95% CI, 15.5%-16.2%) in patients with COVID-19 before vaccine availability (risk difference, 1.4% [95% CI, 1.0%-2.3%]) and 16.3% (95% CI, 16.0%-16.6%) in patients with COVID-19 during vaccine availability (risk difference, 1.9% [95% CI, 1.1%-2.7%]). Compared with patients with influenza, the risk of arterial thromboembolism was not significantly higher among patients with COVID-19 before vaccine availability (adjusted HR, 1.04 [95% CI, 0.97-1.11]) or during vaccine availability (adjusted HR, 1.07 [95% CI, 1.00-1.14]). The 90-day absolute risk of venous thromboembolism was 5.3% (95% CI, 4.9%-5.8%) in patients with influenza vs 9.5% (95% CI, 9.2%-9.7%) in patients with COVID-19 before vaccine availability (risk difference, 4.1% [95% CI, 3.6%-4.7%]) and 10.9% (95% CI, 10.6%-11.1%) in patients with COVID-19 during vaccine availability (risk difference, 5.5% [95% CI, 5.0%-6.1%]). Compared with patients with influenza, the risk of venous thromboembolism was significantly higher among patients with COVID-19 before vaccine availability (adjusted HR, 1.60 [95% CI, 1.43-1.79]) and during vaccine availability (adjusted HR, 1.89 [95% CI, 1.68-2.12]).Conclusions and RelevanceBased on data from a US public health surveillance system, hospitalization with COVID-19 before and during vaccine availability, vs hospitalization with influenza in 2018-2019, was significantly associated with a higher risk of venous thromboembolism within 90 days, but there was no significant difference in the risk of arterial thromboembolism within 90 days.

The U.S. Food and Drug Administration (FDA) approved the first chimeric antigen receptor T-cell therapy, tisagenlecleucel, in August 2017. We sought to describe adverse events (AEs) reported to the FDA Adverse Event Reporting System (FAERS) for tisagenlecleucel in the post-marketing period. We searched FAERS reports to identify U.S. patients treated with tisagenlecleucel between August 30, 2017-August 31, 2019. We reviewed individual reports, calculated AE frequencies and reporting rates (RRs), and used Empirical Bayesian Geometric Mean methods to identify disproportionate reporting. We identified 646 de-duplicated reports with a median age at AE of 18 (interquartile range: 11-56) years. The overall RR was 81.0%, and more than 95% of reports described a serious outcome. Cytokine release syndrome (CRS) was the most frequently reported AE (51.1%) with a RR of 41.4%; neurotoxicity was reported less frequently (21.2%), with a RR of 17.2%. Most disproportionately reported AEs were listed on the package insert or confounded by indication. We identified 13 subsequent neoplasms (SPN), the majority occurring within six months of tisagenlecleucel administration, and none reporting evidence of insertional mutagenesis. A total of 165 reports (26%) described a death outcome; most deaths occurred >30 days after treatment. The majority of deaths (64%) were due to progression of the underlying lymphoid neoplasm, and few (

This study uses 2 large US health care claims databases (Medicare fee-for-service and the US Food and Drug Administration’s Sentinel System) to examine systemic corticosteroid use among nonhospitalized patients with COVID-19.

Background In October 2014, MenB-FHbp (Trumenba, Pfizer) became the first meningococcal group B vaccine licensed in the United States. It is approved for use in individuals aged 10–25 years. Our objective was to evaluate the safety of MenB-FHbp postlicensure. Methods The Vaccine Adverse Event Reporting System (VAERS) is a national passive vaccine safety surveillance system. We analyzed US VAERS reports for MenB-FHbp received from the date of licensure in October 2014 through December 2018. We described the characteristics of the persons and adverse events (AEs) reported and calculated reporting rates using the number of doses distributed. We used empirical Bayesian data mining to identify AEs reported at least twice as often as expected compared with all other vaccines. Results VAERS received 2106 reports involving MenB-FHbp, representing 698 reports per million doses distributed. The median age of vaccinees was 17 years, and 55% were female. MenB-FHbp was given simultaneously with other vaccines in 37% of reports. Most reports (57%) described AEs that started on the day of or day after vaccination. The most common AEs reported were pyrexia (27%), headache (25%), and pain (16%). There were 44 serious reports (2% of all reports), among which 42 reported a hospitalization. Data mining identified disproportional reporting of headache, pyrexia, chills, and myalgia. Conclusions The AEs most commonly or disproportionately reported following MenB-FHbp were consistent with those identified in clinical trials as described in the US package insert. We did not identify any new safety issues.

Background Global efforts to adequately monitor safety of new vaccines for pregnant women in low and middle-income countries (LMICs) are needed. The Global Alignment of Immunization Safety Assessment in pregnancy (GAIA) project recently published case definitions based on levels of diagnostic certainty for pregnancy- and neonatal outcomes and maternal vaccination. As a preliminary step to assessing the applicability of these definitions in LMICs, WHO selected sites and conducted a feasibility assessment to evaluate their ability to identify and classify selected outcomes (preterm birth, neonatal death, neonatal invasive bloodstream infection (NI-BSI), stillbirth) and maternal vaccination. Methods Candidate sites were initially screened using a questionnaire. For each outcome, eligible sites were asked to retrospectively identify and collect information for three individuals born in 2016. Subsequently, outcomes were classified by level of diagnostic certainty. Results Fifty-one sites (15 countries) were screened; 32 of them (9 countries) participated in the assessment and identified 315 subjects with the outcomes of interest. Twenty-four sites (8 countries) identified at least one subject per outcome and agreed to continue participating. The majority (80%) of preterm births, neonatal deaths, and NI-BSI subjects, but only 50% of stillbirths, could be assessed for diagnostic certainty. The main reasons for not classifying stillbirths were insufficient information to distinguish between antepartum and intrapartum stillbirth (29%); or that not all data for one subject fit into a single level of diagnostic certainty (35%). Forty-nine percent of mothers were considered vaccinated, 6% not-vaccinated, and vaccination status could not be assessed in 44% of them. Discussion GAIA case definitions for four neonatal outcomes and maternal vaccination were successfully piloted in 24 sentinel sites across four WHO regions. Our assessment found that modification of the stillbirth definition could help avoid potential misclassification. Vaccine safety monitoring in LMICs will benefit from systematic recording of all vaccinations during pregnancy.

New vaccines designed to prevent diseases endemic in low and middle-income countries (LMICs) are now being introduced without prior record of utilization in countries with robust pharmacovigilance systems. To address this deficit, our objective was to demonstrate feasibility of an international hospital-based network for the assessment of potential epidemiological associations between serious and rare adverse events and vaccines in any setting. This was done through a proof-of-concept evaluation of the risk of immune thrombocytopenic purpura (ITP) and aseptic meningitis (AM) following administration of the first dose of measles-mumps-containing vaccines using the self-controlled risk interval method in the primary analysis. The World Health Organization (WHO) selected 26 sentinel sites (49 hospitals) distributed in 16 countries of the six WHO regions. Incidence rate ratios (IRR) of 5.0 (95% CI: 2.5–9.7) for ITP following first dose of measles-containing vaccinations, and of 10.9 (95% CI: 4.2–27.8) for AM following mumps-containing vaccinations were found. The strain-specific analyses showed significantly elevated ITP risk for measles vaccines containing Schwarz (IRR: 20.7; 95% CI: 2.7–157.6), Edmonston-Zagreb (IRR: 11.1; 95% CI: 1.4–90.3), and Enders’Edmonston (IRR: 8.5; 95% CI: 1.9–38.1) strains. A significantly elevated AM risk for vaccines containing the Leningrad-Zagreb mumps strain (IRR: 10.8; 95% CI: 1.3–87.4) was also found. This proof-of-concept study has shown, for the first time, that an international hospital-based network for the investigation of rare vaccine adverse events, using common standardized procedures and with high participation of LMICs, is feasible, can produce reliable results, and has the potential to characterize differences in risk between vaccine strains. The completion of this network by adding large reference hospitals, particularly from tropical countries, and the systematic WHO-led implementation of this approach, should permit the rapid post-marketing evaluation of safety signals for serious and rare adverse events for new and existing vaccines in all settings, including LMICs. Center for Biologics Evaluation and Research (CBER)-U.S. Food and Drug Administration (FDA) funded this project (Grant number U01 FD004575). GRiP, Global Research in Pediatrics, European Union Seventh framework Programme (FP7/2007-2013) provided additional funding under grant agreement nº 261060.

Background Rotavirus vaccines are available in Spain from 2007. They are recommended by the Spanish Pediatric Association, but not funded by the National Health System (NHS) and its coverage rate reached 40-50%. The hospitalization rate reduction of rotavirus caused gastroenteritis (RVAGE) directly attributable to vaccination remains unclear due to the large differences described in published studies, ranging from 14 to 44.5% in children

Introduction The Advisory Committee on Immunization Practices (ACIP) recommends vaccination with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Tdap) in persons ≥65 years of age. To date, few studies have assessed the safety of Tdap in this population. We aimed to summarize reports submitted to the Vaccine Adverse Event Reporting System (VAERS) following receipt of Tdap in this age group. Methods We searched for and analyzed U.S. VAERS reports of Tdap among individuals ≥65 years of age submitted from September 1, 2010 through December 31, 2018. We classified reports according to concurrent vaccination, seriousness, and outcome (death, non-death) and determined the frequency of reported adverse events (AEs). For serious reports, we reviewed available medical records. Data mining analyses were undertaken to detect disproportionality in reporting. Results VAERS received a total of 1,798 reports following Tdap, of which 104 (6%) were serious. The most common AEs were injection site erythema (26%; n = 468), injection site pain (19%; n = 335), injection site swelling (18%; n = 329), and erythema (18%; n = 321). We identified seven deaths; none were attributed to Tdap. Among serious non-death reports, nervous system disorders (35.1%; n = 34) and infections and infestations (n = 18.6%; n = 18) were most commonly reported. Data mining did not identify any vaccine-AE combination reported more frequently than expected. Conclusions We did not identify any new safety concern over nearly a decade of recommended Tdap use among adults ≥65 years of age. Findings from this post-marketing review are consistent with prior post-marketing observations and pre-licensure studies.

Human papillomavirus (HPV) infection contributes to the pathogenesis of oropharyngeal squamous cell carcinomas. We estimated prevalence and six-month persistence of oral HPV infections among university students ages 18–25 years living in Valencia, Spain, during the 2012–2013 academic year. Participants provided oral rinse samples; HPV-positive subjects provided a follow-up sample. The study included 543 students; 70 (12.9%) women had received HPV vaccination. Prevalence among vaccinees and non-vaccinees were 10.0% (95% CI: 4.1–19.5%) and 6.8% (95% CI: 4.7–9.4%), respectively. All HPV infections among vaccinees were non-typeable genotypes; 59.4% of non-vaccinees had high-risk genotype infections. Follow-up samples were obtained from 36 participants; one vaccinee (whose specimen was non-typeable) and seven non-vaccinees were found to be HPV positive. Among non-vaccinees, six-month persistence was 10.3% (95% CI: 2.2–27.4%); all persistent infections were with high-risk genotypes. Our results, although subject to study limitations, may support the need to implement new public health strategies.

Background The U.S. Food and Drug Administration and the Centers for Medicare & Medicaid Services have been actively monitoring the risk of Guillain-Barre syndrome (GBS) following influenza vaccination among Fee-for-Service (FFS) Medicare beneficiaries every season since 2008. We present our evaluation of the GBS risk following influenza vaccinations during the 2017–2018 season. Methods We implemented a multilayered approach to active safety surveillance that included near real-time surveillance early in the season, comparing GBS rates post-vaccination during the 2017–2018 season with rates from five prior seasons using the Updating Sequential Probability Ratio Test (USPRT), and end-of-season self-controlled risk interval (SCRI) analyses. Results We identified approximately 16 million influenza vaccinations. The near real-time surveillance did not signal for a potential 2.5-fold increased GBS risk either in days 8–21 or 1–42 post-influenza vaccination. In the SCRI analyses, we did not detect statistically significant increased GBS risks among influenza-vaccinated Medicare beneficiaries ≥65 years for either the 8–21 or 1–42-day risk windows for all seasonal vaccines combined, high-dose vaccine, or standard-dose vaccines; we did detect an increased GBS risk in days 8–21 post-vaccination for individuals vaccinated with the adjuvanted vaccine (OR: 3.75; 95% CI: 1.01, 13.96), although this finding was not statistically significant after multiplicity adjustment (p = 0.146). Conclusions Our multilayered surveillance approach—which allows for early detection of elevated GBS risk and provides reliable end-of-season SCRI estimates of effect size—did not identify an increased GBS risk following 2017–2018 influenza vaccinations. The slightly increased GBS risk with the adjuvanted vaccine, which was not statistically significant following multiplicity adjustment, is consistent with the package inserts of all U.S.-licensed influenza vaccines, which warn of a potential low increased GBS risk. The benefits of influenza vaccines in preventing morbidity and mortality heavily outweigh this potential risk.

Purpose The US Food and Drug Administration monitors the risk of Guillain-Barre syndrome (GBS) following influenza vaccination using several data sources including Medicare. In the 2017 to 2018 season, we transitioned our near real-time surveillance in Medicare to more effectively detect large GBS risk increases early in the season while avoiding false positives. Methods We conducted a simulation study examining the ability of the updating sequential probability ratio test (USPRT) to detect substantially elevated GBS risk in the 8- to 21-day postvaccination versus 5× to 30× the historical rate. We varied the first testing week (weeks 5-8) and the null rate (1×-3×) and evaluated power. We estimated signal probability and the risk ratio (RR) after signaling when high-risk seasons were rare. Results Applying fixed alternatives, we found >80% power to detect a risk 30× the historical rate in week 5 for the 1× null and in week 6 for the 1.5× to 3× nulls. Nearly all testing schedules had >80% power for a 5× risk by week 11. To test the robustness of USPRT, we further simulated seasons where 1% were true high-risk seasons. Using a 1× null led to 10% of seasons signaling by week 11 (median RR approximately 1.4), which decreased to approximately 1% with the ≥2.5× null (median RR approximately 16.0). Conclusions On the basis of the results from this simulation and subsequent consultations with experts and stakeholders, we specified USPRT to test continuously from weeks 7 to 11 using the null hypothesis that the observed GBS rate was 2.5× the historical rate. This helped improve the ability of USPRT to provide early detection of GBS risk following influenza vaccination as part of a multilayered system of surveillance.

OBJECTIVE: To assess the safety of currently licensed diphtheria-tetanus-acellular pertussis (DTaP) vaccines in the United States by using data from the Vaccine Adverse Event Reporting System (VAERS), a spontaneous reporting surveillance system. METHODS: We searched VAERS for US reports of DTaP vaccinations occurring from January 1, 1991, through December 31, 2016, and received by March 17, 2017. We reviewed available medical records for all death reports and a random sample of reports classified as nondeath serious. We used Empirical Bayesian data mining to identify adverse events that were disproportionally reported after DTaP vaccination. RESULTS: VAERS received 50 157 reports after DTaP vaccination; 43 984 (87.7%) of them reported concomitant administration of other vaccines, and 5627 (11.2%) were serious. Median age at vaccination was 19 months (interquartile range 35 months). The most frequently reported events were injection site erythema (12 695; 25.3%), pyrexia (9913; 19.8%), injection site swelling (7542; 15.0%), erythema (5599; 11.2%), and injection site warmth (4793; 9.6%). For 3 of the DTaP vaccines, we identified elevated values for vaccination errors using Empirical Bayesian data mining. CONCLUSIONS: No new or unexpected adverse events were detected. The observed disproportionate reporting for some nonserious vaccination errors calls for better education of vaccine providers on the specific indications for each of the DTaP vaccines.

Background Studies of vaccine effectiveness (VE) rely on accurate identification of vaccination and cases of vaccine-preventable disease. In practice, diagnostic tests, clinical case definitions and vaccination records often present inaccuracies, leading to biased VE estimates. Previous studies investigated the impact of non-differential disease misclassification on VE estimation. Methods We explored, through simulation, the impact of non-differential and differential disease- and exposure misclassification when estimating VE using cohort, case-control, test-negative case-control and case-cohort designs. The impact of misclassification on the estimated VE is demonstrated for VE studies on childhood seasonal influenza and pertussis vaccination. We additionally developed a web-application graphically presenting bias for user-selected parameters. Results Depending on the scenario, the misclassification parameters had differing impacts. Decreased exposure specificity had greatest impact for influenza VE estimation when vaccination coverage was low. Decreased exposure sensitivity had greatest impact for pertussis VE estimation for which high vaccination coverage is typically achieved. The impact of the exposure misclassification parameters was found to be more noticeable than that of the disease misclassification parameters. When misclassification is limited, all study designs perform equally. In case of substantial (differential) disease misclassification, the test-negative design performs worse. Conclusions Misclassification can lead to significant bias in VE estimates and its impact strongly depends on the scenario. We developed a web-application for assessing the potential (joint) impact of possibly differential disease- and exposure misclassification that can be modified by users to their own study scenario. Our results and the simulation tool may be used to guide better design, conduct and interpretation of future VE studies.

Timely and effective evaluation of vaccine safety signals for newly developed vaccines introduced in low and middle- income countries (LMICs) is essential. The study tested the development of a global network of hospital-based sentinel sites for vaccine safety signal verification and hypothesis testing. Twenty-six sentinel sites in sixteen countries across all WHO regions participated, and 65% of the sites were from LMIC. We describe the process for the establishment and operationalization of such a network and the lessons learned in conducting a multi-country collaborative initiative. 24 out of the 26 sites successfully contributed data for the global analysis using standardised tools and procedures. Our study successfully confirmed the well-known risk estimates for the outcomes of interest. The main challenges faced by investigators were lack of adequate information in the medical records for case ascertainment and classification, and access to immunization data. The results suggest that sentinel hospitals intending to participate in vaccine safety studies strengthen their systems for discharge diagnosis coding, medical records and linkage to vaccination data. Our study confirms that a multi-country hospital-based network initiative for vaccine safety monitoring is feasible and demonstrates the validity and utility of large collaborative international studies to monitor the safety of new vaccines introduced in LMICs.

Resumen: Introducción: Los objetivos de este estudio fueron describir las notificaciones de sospechas de reacciones adversas relacionadas con las vacunas frente a rotavirus y valorar la sensibilidad de la notificación para invaginación intestinal. Material y métodos: Estudio descriptivo, a partir de las notificaciones de sospechas de reacciones adversas relacionadas con las vacunas frente a rotavirus, ocurridas en niños menores de diez meses, registradas en el Centro de Farmacovigilancia de la Comunidad Valenciana durante el periodo 2007-2011.Se comparó la tasa de notificación de invaginaciones con la tasa de invaginaciones en vacunados obtenida utilizando la base de datos de altas hospitalarias (CMBD) y el registro nominal de vacunaciones autonómico. Resultados: La tasa de notificación de eventos adversos fue de 20 por 100.000 dosis administradas. El 74% de las notificaciones se clasificaron como no graves, siendo la fiebre, los vómitos y la diarrea las sospechas más frecuentes. Dos casos de invaginación, ocurridos en los siete primeros días tras la vacunación, fueron notificados como asociados temporalmente a la vacunación. La sensibilidad de la notificación de invaginación intestinal para el periodo de riesgo de uno a siete días fue del 50%. Conclusiones: Los resultados sugieren que las vacunas frente a rotavirus presentan un perfil de seguridad en general adecuado, y que el Centro de Farmacovigilancia de la Comunidad Valenciana, comparado con otros sistemas de vigilancia pasiva, es igualmente sensible para detectar señales de posible asociación con invaginación intestinal. Este riesgo requiere ser investigado con estudios epidemiológicos bien diseñados y comparado con los evidentes beneficios que estas vacunas proporcionan. Abstract: Introduction: The aims of this study were to describe the reports of suspected adverse events due to rotavirus vaccines, and assess the reporting sensitivity for intussusception. Material and methods: Descriptive study performed using the reports of suspected adverse events following rotavirus vaccination in infants aged less than 10 months, as registered in the Pharmacovigilance Centre of the Valencian Community during 2007-2011.The reporting rate for intussusception was compared to the intussusception rate in vaccinated infants obtained using the hospital discharge database (CMBD), and the regional vaccine registry. Results: The adverse event reporting rate was 20 per 100,000 administered doses, with the majority (74%) of the reports being classified as non-serious. Fever, vomiting, and diarrhea were the adverse events reported more frequently. Two intussusception cases, which occurred within the first seven days post-vaccination, were reported as temporarily associated to vaccination. The reporting sensitivity for intussusception at the Pharmacovigilance Centre in the 1-7 day interval following rotavirus vaccination was 50%. Conclusions: Our results suggest that rotavirus vaccines have, in general, a good safety profile. Intussusception reporting to the Pharmacovigilance Centre shows sensitivity similar to other passive surveillance systems. The intussusception risk should be further investigated using well-designed epidemiological studies, and evaluated in comparison with the well-known benefits provided by these vaccines.

Introduction: The aims of this study were to describe the reports of suspected adverse events due to rotavirus vaccines, and assess the reporting sensitivity for intussusception. Materials and methods: Descriptive study performed using the reports of suspected adverse events following rotavirus vaccination in infants aged less than 10 months, as registered in the Pharmacovigilance Centre of the Valencian Community during 2007–2011.The reporting rate for intussusception was compared to the intussusception rate in vaccinated infants obtained using the hospital discharge database (CMBD) and the regional vaccine registry. Results: The adverse event reporting rate was 20 per 100,000 administered doses, with the majority (74%) of the reports being classified as non-serious. Fever, vomiting, and diarrhoea were the adverse events reported more frequently. Two intussusception cases, which occurred within the first seven days post-vaccination, were reported as temporarily associated to vaccination. The reporting sensitivity for intussusception at the Pharmacovigilance Centre in the 1–7 day interval following rotavirus vaccination was 50%. Conclusions: Our results suggest that rotavirus vaccines have, in general, a good safety profile. Intussusception reporting to the Pharmacovigilance Centre shows sensitivity similar to other passive surveillance systems. The intussusception risk should be further investigated using well-designed epidemiological studies, and evaluated in comparison with the well-known benefits provided by these vaccines. Resumen: Introducción: Los objetivos de este estudio fueron describir las notificaciones de sospechas de reacciones adversas relacionadas con las vacunas frente a rotavirus y valorar la sensibilidad de la notificación para invaginación intestinal. Material y métodos: Estudio descriptivo, a partir de las notificaciones de sospechas de reacciones adversas relacionadas con las vacunas frente a rotavirus, ocurridas en niños menores de diez meses, registradas en el Centro de Farmacovigilancia de la Comunidad Valenciana durante el periodo 2007-2011.Se comparó la tasa de notificación de invaginaciones con la tasa de invaginaciones en vacunados obtenida utilizando la base de datos de altas hospitalarias (CMBD) y el registro nominal de vacunaciones autonómico. Resultados: La tasa de notificación de eventos adversos fue de 20 por 100.000 dosis administradas. El 74% de las notificaciones se clasificaron como no graves, siendo la fiebre, los vómitos y la diarrea las sospechas más frecuentes. Dos casos de invaginación, ocurridos en los siete primeros días tras la vacunación, fueron notificados como asociados temporalmente a la vacunación. La sensibilidad de la notificación de invaginación intestinal para el periodo de riesgo de uno a siete días fue del 50%. Conclusiones: Los resultados sugieren que las vacunas frente a rotavirus presentan un perfil de seguridad en general adecuado, y que el Centro de Farmacovigilancia de la Comunidad Valenciana, comparado con otros sistemas de vigilancia pasiva, es igualmente sensible para detectar señales de posible asociación con invaginación intestinal. Este riesgo requiere ser investigado con estudios epidemiológicos bien diseñados y comparado con los evidentes beneficios que estas vacunas proporcionan.

Importance Sipuleucel-T was the first therapeutic cancer vaccine approved by the US Food and Drug Administration (FDA) in 2010. Although almost a decade has passed since its approval for the treatment of asymptomatic or minimally symptomatic castration-resistant prostate cancer (CRPC), there remains a paucity of literature describing safety data in the postmarketing period. Objective To describe the postmarketing safety experience for sipuleucel-T. Design, Setting, and Participants In this case series study, US reports for sipuleucel-T submitted to the FDA’s Adverse Event Reporting System were searched and reviewed between April 29, 2010, and December 31, 2017. This system is a spontaneous safety surveillance database for drug and therapeutic biologic products. The analysis of 3216 reports and select case reviews were undertaken between February and November 2018. Main Outcomes and Measures Descriptive statistics were used to assess adverse event reports for sipuleucel-T. Empirical Bayes Geometric Means (EBGM) and their 90% confidence intervals (CIs) were computed to identify disproportionate (ie, at least twice the expected) reporting of sipuleucel-T–event pairs. Selected adverse events and death reports were individually reviewed. Results In total, 3216 reports were identified for sipuleucel-T, of which 2014 (62.6%) were serious. For all included reports, the patients’ median (interquartile range) age was 73 (67-79) years, and 3149 were specified to be males. Chills (n = 318), malaise (n = 196), pyrexia (n = 189), culture positive (n = 184), fatigue (n = 180), and nausea (n = 173) were among the most commonly reported adverse events. Infusion-related reactions (EBGM, 12.1; 90% CI, 9.4-15.3), infections, vascular events, and transient ischemic attacks (EBGM, 2.9; 90% CI, 2.2-3.9) were reported disproportionately. Among 249 deaths for which relevant dates were available, 128 (51.4%) were reported within 30 days of a sipuleucel-T infusion, of which 81.2% included a specified cause of death; of these 104 deaths, there were 37 neoplasms (35.6%), 25 cardiac disorders (24.0%), 18 nervous system disorders (17.3%), and 9 infections (8.7%). Conclusions and Relevance Reported adverse events were generally consistent with the safety experience observed in prelicensure studies and described in the sipuleucel-T package insert. Off-label use among overtly symptomatic men with CRPC, reporting bias, or lack of product effectiveness may have influenced the reporting of deaths within 30 days of treatment initiation. With this overview of sipuleucel-T experience, the present study serves as a resource for health care professionals and patients as they weigh the risks and benefits of treatment in the context of all available therapeutic options for CRPC.

Background: Adjuvanted influenza vaccines offer greater and broader immunogenicity to older adults than conventional vaccines. Studies assessing the comparative effectiveness of adjuvanted influenza vaccines in this age group are lacking. Methods: We conducted a retrospective cohort study to estimate the comparative effectiveness of MF59-adjuvanted trivalent influenza vaccine (TIV) and virosomal-TIV for prevention of influenza hospitalization in adults aged >= 65 years. We obtained administrative data on immunization status and influenza hospitalization for the 2010-2011 influenza season. We used Cox regression models to assess comparative effectiveness; crude and adjusted by age, sex, comorbidity, deprivation, type of insurance, and travel time to hospital. We accounted for data clustering at the hospital level by using a multilevel random effects model. Results: Overall, 373,798 vaccinated subjects were evaluated. There were 40 hospitalizations for influenza among 176,618 subjects, contributing 4,288,109 person-weeks at risk in the virosomal-TIV group, and 37 hospitalizations for influenza among 197,180 subjects, contributing 4,786,360 person-weeks at risk in the MF59-TIV group. The crude hazard ratio (HR) was 0.83 (0.53-1.30), and the adjusted Cox estimated HR of MF59-TIV relative to virosomal-TIV was 0.86 (0.55-1.35). After accounting for data clustering, the HR of influenza hospitalization associated with MF59-TIV relative to virosomal-TIV was 0.94(0.37-2.38). Conclusion: During the 2010-2011 influenza season, we found no differences in the risk of influenza hospitalization in subjects aged >= 65 years vaccinated with MF59-TIV compared with those vaccinated with virosomal-TIV. (C) 2013 Elsevier Ltd. All rights reserved.

Background Over recent decades, the Region of the Americas has made significant progress towards hepatitis B elimination. We summarize the countries/territories’ efforts in introducing and implementing hepatitis B (HB) vaccination and in evaluating its impact on HB virus seroprevalence. Methods We collected information about HB vaccination schedules, coverage estimates, and year of vaccine introduction from countries/territories reporting to the Pan American Health Organization/World Health Organization (PAHO/WHO) through the WHO/UNICEF Joint Reporting Form on Immunization. We obtained additional information regarding countries/territories vaccination recommendations and strategies through communications with Expanded Program on Immunization (EPI) managers and national immunization survey reports. We identified vaccine impact studies conducted and published in the Americas. Results As of October 2016, all 51 countries/territories have included infant HB vaccination in their official immunization schedule. Twenty countries, whose populations represent over 90% of the Region’s births, have included nationwide newborn HB vaccination. We estimated at 89% and 75%, the regional three-dose series and the birth dose HB vaccination coverage, respectively, for 2015. The impact evaluations of infant HB immunization programs in the Region have shown substantial reductions in HB surface antigen (HBsAg) seroprevalence. Conclusion The achievements of vaccination programs in the Americas suggest that the elimination of perinatal and early childhood HB transmission could be feasible in the short-term. Moreover, the data gathered indicate that the Region may have already achieved the 2020 WHO goal for HB control.

Highlights ► We perform a case–case comparison as an improvement of the test-negative design. ► We report IVE estimates with a low probability of bias. ► Influenza vaccination halved the risk of confirmed influenza hospitalization. ► This effect was consistent regardless of age over 60. ► The measured effect was specific for confirmed influenza hospitalizations., Introduction We estimated influenza vaccine effectiveness (IVE) to prevent laboratory-confirmed influenza-related hospitalizations in patients 18 years old or older during the 2010–2011 influenza season. Methods We conducted a prospective case-control study in five hospitals, in Valencia, Spain. Study subjects were consecutive emergency hospitalizations for predefined conditions associated with an influenza-like illness episode

There is a lack of European epidemiologic population-based studies on bronchiolitis and respiratory syncytial virus (RSV) bronchiolitis including both hospitalizations and primary care attendance.A retrospective cohort of all children born between 2009 and 2012 was followed from birth to 2 years of age using population and health databases. We searched for global bronchiolitis (International Classification of Diseases, 9th revision, Clinical Modification codes 466.1, 466.11 and 466.19) and RSV bronchiolitis (code 466.11 and code 466.19 with positive RSV test) in the first appearance either in primary care or in hospitalization databases. A preterm subcohort (International Classification of Diseases, 9th revision, Clinical Modification codes 765) was also analyzed.The cohort consisted of 198,223 children of whom 41,479 were diagnosed of bronchiolitis (incidence rate 16.4/100 children2 years per year). Of those, 5390 were hospitalized with the majority of hospitalizations occurring at6 months of age (incidence rate of 5.2/100 children6 months per year) and 3106 of the hospitalizations were RSV positive (incidence rate 3.2/100 children6 months per year). RSV hospitalizations were 26% longer than non-RSV. In preterm infants, hospitalization incidence was more than double, and the mean length of hospitalization was 29% longer.Most (87%) bronchiolitis cases are managed in primary care offices. Approximately 2 out of every 10 children2 are diagnosed of bronchiolitis, 3 out of every 100 are hospitalized and 1.6 out of every 100 are hospitalized with RSV bronchiolitis in our cohort. Infants between 2 and 10 weeks constitute a risk group for severe bronchiolitis.

Vacunación; Narcolepsia; Simulación y modelado: en Vacunació; Narcolèpsia; Simulació i modelització Vaccination; Narcolepsy; Simulation and modeling Background & objectives Vaccine safety signals require investigation, which may be done rapidly at the population level using ecological studies, before embarking on hypothesis-testing studies. Incidence rates were used to assess a signal of narcolepsy following AS03-adjuvanted monovalent pandemic H1N1 (pH1N1) influenza vaccination among children and adolescents in Sweden and Finland in 2010. We explored the utility of ecological data to assess incidence of narcolepsy following exposure to pandemic H1N1 virus or vaccination in 10 sites that used different vaccines, adjuvants, and had varying vaccine coverage. Methods We calculated incidence rates of diagnosed narcolepsy for periods defined by influenza virus circulation and vaccination campaign dates, and used Poisson regression to estimate incidence rate ratios (IRRs) comparing the periods during which wild-type virus circulated and after the start of vaccination campaigns vs. the period prior to pH1N1 virus circulation. We used electronic health care data from Sweden, Denmark, the United Kingdom, Canada (3 provinces), Taiwan, Netherlands, and Spain (2 regions) from 2003 to 2013. We investigated interactions between age group and adjuvant in European sites and conducted a simulation study to investigate how vaccine coverage, age, and the interval from onset to diagnosis may impact the ability to detect safety signals. Results Incidence rates of narcolepsy varied by age, continent, and period. Only in Taiwan and Sweden were significant time-period-by-age-group interactions observed. Associations were found for children in Taiwan (following pH1N1 virus circulation) and Sweden (following vaccination). Simulations showed that the individual-level relative risk of narcolepsy was underestimated using ecological methods comparing post- vs. pre-vaccination periods; this effect was attenuated with higher vaccine coverage and a shorter interval from disease onset to diagnosis. Conclusions Ecological methods can be useful for vaccine safety assessment but the results are influenced by diagnostic delay and vaccine coverage. Because ecological methods assess risk at the population level, these methods should be treated as signal-generating methods and drawing conclusions regarding individual-level risk should be avoided. Antecedents i objectius Els senyals de seguretat per les vacunes requereixen una investigació, que es pot fer ràpidament a nivell de població mitjançant estudis ecològics, abans d'iniciar estudis de prova d'hipòtesi. Les taxes d'incidència es van utilitzar per avaluar un senyal de narcolèpsia després de la vacunació contra la influença pandèmica monovalent H1N1 (pH1N1) adjuvant de AS03 en nens i adolescents a Suècia i Finlàndia el 2010. Explorem la utilitat de les dades ecològiques per avaluar la incidència de la narcolèpsia després de l'exposició a la pandèmia H1N1 virus o vacunació en 10 llocs que utilitzaven diferents vacunes, coadjuvants i tenien una cobertura de vacunes variable. Mètodes Es van calcular les taxes d'incidència de la narcolèpsia diagnosticada per períodes definits per la circulació del virus de la influença i les dates de la campanya de vacunació, i es va utilitzar la regressió de Poisson per estimar les taxes de taxa d'incidència (IRR) que comparaven els períodes durant els quals circulava el virus de tipus salvatge i després de començar campanyes de vacunació contra. el període anterior a la circulació del virus PH1N1. Utilitzem dades d'assistència sanitària electrònica de Suècia, Dinamarca, Regne Unit, Canadà (3 províncies), Taiwan, Països Baixos i Espanya (2 regions) de 2003 a 2013. Es van investigar les interaccions entre grups d'edat i adjuvants en llocs europeus i es va dur a terme una estudi de simulació per investigar com la cobertura de la vacuna, l'edat i l'interval des de l'inici fins al diagnòstic poden afectar la capacitat de detectar senyals de seguretat. Resultats Les taxes d'incidència de la narcolepsia variaven segons l'edat, el continent i el període. Només a Taiwan i Suècia es van observar importants interaccions entre grups de temps i edat. Es van trobar associacions per a nens a Taiwan (després de la circulació del virus pH1N1) i de Suècia (després de la vacunació). Les simulacions van demostrar que el risc relatiu de la narcolepsia a nivell individual es subestimava mitjançant mètodes ecològics que comparaven els períodes post-versus pre-vacunació; aquest efecte es va atenuar amb una major cobertura de vacunes i un interval més curt d'inici de la malaltia al diagnòstic. Conclusions Els mètodes ecològics poden ser útils per a l'avaluació de la seguretat de la vacuna, però els resultats estan influïts per la demora diagnòstica i la cobertura de la vacuna. Atès que els mètodes ecològics avaluen el risc a nivell de la població, aquests mètodes han de ser tractats com a mètodes generadors de senyals i s'han d'extreure conclusions sobre el risc individual. Antecedentes y objetivos Las señales de seguridad de la vacuna requieren una investigación, que se puede hacer rápidamente a nivel de la población utilizando estudios ecológicos, antes de emprender estudios de prueba de hipótesis. Las tasas de incidencia se utilizaron para evaluar una señal de narcolepsia después de la vacunación contra la influenza H1N1 (pH1N1) pandovalente con adyuvante AS03 en niños y adolescentes en Suecia y Finlandia en 2010. Exploramos la utilidad de los datos ecológicos para evaluar la incidencia de narcolepsia después de la exposición a H1N1 pandémica virus o vacunación en 10 sitios que utilizaron diferentes vacunas, adyuvantes y tenían una cobertura de vacunas variable. Métodos Calculamos las tasas de incidencia de narcolepsia diagnosticada para los períodos definidos por la circulación del virus de la influenza y las fechas de las campañas de vacunación, y utilizamos la regresión de Poisson para estimar las tasas de incidencia (IRR) comparando los períodos durante los cuales el virus de tipo salvaje circuló y después del inicio de las campañas de vacunación vs. El período anterior a la circulación del virus pH1N1. Utilizamos datos electrónicos de atención médica de Suecia, Dinamarca, Reino Unido, Canadá (3 provincias), Taiwán, Países Bajos y España (2 regiones) desde 2003 hasta 2013. Investigamos las interacciones entre el grupo de edad y el adyuvante en sitios europeos y realizamos una estudio de simulación para investigar cómo la cobertura de la vacuna, la edad y el intervalo desde el inicio hasta el diagnóstico pueden afectar la capacidad de detectar señales de seguridad. Resultados Las tasas de incidencia de narcolepsia variaron según la edad, el continente y el período. Solo en Taiwán y Suecia se observaron interacciones significativas período-tiempo-por-edad. Se encontraron asociaciones para niños en Taiwán (después de la circulación del virus pH1N1) y Suecia (después de la vacunación). Las simulaciones mostraron que el riesgo relativo a nivel individual de narcolepsia se subestimó utilizando métodos ecológicos que comparan los períodos post-vacunación versus pre-vacunación; este efecto se atenuó con una mayor cobertura de la vacuna y un intervalo más corto desde el inicio de la enfermedad hasta el diagnóstico. Conclusiones Los métodos ecológicos pueden ser útiles para la evaluación de la seguridad de la vacuna, pero los resultados están influenciados por el retraso en el diagnóstico y la cobertura de la vacuna. Debido a que los métodos ecológicos evalúan el riesgo a nivel de la población, estos métodos deben tratarse como métodos generadores de señales y deben evitarse conclusiones extraordinarias con respecto al riesgo a nivel individual.

Background Although rotavirus vaccines have been licensed in Spain for over 8 years, they are not funded by its public health systems. The analysis of their effectiveness in the Valencia Region could better inform decisions about potential inclusion in the official immunization schedule. Our aim was to assess the effectiveness of Rotarix® (RV1) and RotaTeq® (RV5) against rotavirus hospitalizations. Methods We conducted a retrospective cohort study using the region’s health care databases, among resident children aged

Studies have shown high intussusception rates in Spain. We performed a hospital-based retrospective observational study of the intussusception risk following rotavirus vaccinations among infants in Valencia, a region of Spain with an annual birth cohort of approximately 48,000 children, during 2007-2011, using a self-controlled case series design. We performed medical record review of all cases using Brighton Collaboration's case definition and assessed the positive predictive value (PPV) of the intussusception diagnosis code. Among 151 hospitalized cases discharged as intussusception, we confirmed 136 as Brighton Collaboration's Levels 1 or 2, resulting in a PPV of 93% (95% CI: 87%-96%). Three confirmed cases occurred within days 1-7 following the first rotavirus vaccination. The incidence rate ratio was 9.0 (95% CI: 0.9-86.5) (crude) and 4.7 (95% CI:0.3-74.1)(age adjusted). In this first study in Europe, the intussusception risk point estimate was comparable to other studies, although results were not statistically significant, maybe due to limited power. The high PPV found will facilitate implementation of a larger study without requiring medical record review. Our finding of very few vaccinated cases despite a thorough 5-year investigation in a country that, according to previous studies, may have a large background rate of intussusception is reassuring and should contribute to deliberations about the need to include rotavirus vaccines in the official Spanish calendars.

Resumen: Introducción: En 2009, 2 casos de convulsiones en adolescentes tras la administración de la vacuna tetravalente frente al virus del papiloma humano (VPH) generaron impacto mediático y afectaron negativamente la confianza del público en esta vacuna.Nuestros objetivos fueron describir las sospechas de reacciones adversas (SRA) notificadas al Centro Autonómico de Farmacovigilancia de la Comunidad Valenciana (CAFCV) tras la administración de la vacuna frente al VPH y comparar la tasa de notificación de síncope y convulsiones de esta vacuna con la de otras vacunas administradas en adolescentes. Material y métodos: Estudio descriptivo de las notificaciones de SRA relacionadas con esta vacuna recibidas por el CAFCV entre 2007 y 2011. Resultados: Las manifestaciones clínicas más comunicadas fueron mareos, cefalea y síncope.Las tasas de notificación de síncope o pérdida de conciencia y convulsiones con la vacuna frente al VPH fueron de 17 y 3,2 por 100.000 dosis administradas, respectivamente, y de 15 y 1,6 para síncope o pérdida de conciencia y convulsiones sincopales ocurridas el día de la vacunación. Las tasas de notificación de síncope o pérdida de conciencia y convulsiones fueron de 6,4 y 0,4 para otras vacunas. Conclusiones: Las tasas de notificación de síncope o pérdida de conciencia y convulsiones fueron mayores para la vacuna frente al VPH que para otras vacunas administradas en adolescentes; esto es consistente con la atención mediática originada por la vacuna y con hallazgos de estudios previos. No obstante, la información obtenida sobre las SRA a la vacuna sugiere un buen perfil de seguridad. Abstract: Introduction: In 2009, two cases of seizures in adolescents following quadrivalent human papillomavirus vaccine (qHPV) administration, generated important media attention, and adversely affected public trust in this vaccine. Our objectives were to describe suspected adverse reactions (SARs) reported to the Pharmacovigilance Centre in the Valencian Community (PCVC) after administration of HPV vaccine, and to compare reporting rates of syncope and seizures following this vaccine with those of other vaccines administered to girls aged 13-15 years. Material and methods: Descriptive study of SARs reported following this vaccine to the PCVC between 2007 and 2011. Results: The clinical symptoms most frequently reported were dizziness, headache, and syncope.Reporting rates of syncope or loss of consciousness and seizures with qHPV vaccine were 17 and 3.2 per 100,000 doses administered, respectively, and 15 and 1.6 for syncope or loss of consciousness and syncopal seizures occurred on the day of vaccination. The reporting rates of syncope or loss of consciousness and seizures were 6.4 and 0.4, for the other vaccines. Conclusions: Consistent with the media attention generated, and with results from other studies, the reporting rates of syncope or loss of consciousness and seizures were higher for the HPV vaccine than for other vaccines given in adolescence. Nevertheless, the overall information obtained on SARs following the qHPV vaccine suggests a good safety profile.

Background Most evidence of the effectiveness of influenza vaccines comes from studies conducted in primary care, but less is known about their effectiveness in preventing serious complications. Here, we examined the influenza vaccine effectiveness (IVE) against hospitalization with PCR-confirmed influenza in the predominant A(H3N2) 2011–2012 influenza season. Methods A hospital-based, test-negative study was conducted in nine hospitals in Valencia, Spain. All emergency admissions with a predefined subset of symptoms were eligible. We enrolled consenting adults age 18 and over, targeted for influenza vaccination because of comorbidity, with symptoms of influenza-like-illness within seven days of admission. We estimated IVE as (1-adjusted vaccination odds ratio)*100 after accounting for major confounders, calendar time and recruitment hospital. Results The subjects included 544 positive for influenza A(H3N2) and 1,370 negative for influenza admissions. Age was an IVE modifying factor. Regardless of vaccine administration, IVE was 72% (38 to 88%) in subjects aged under 65 and 21% (−5% to 40%) in subjects aged 65 and over. By type of vaccine, the IVE of classical intramuscular split-influenza vaccine, used in subjects 18 to 64, was 68% (12% to 88%). The IVE for intradermal and virosomal influenza vaccines, used in subjects aged 65 and over, was 39% (11% to 58%) and 16% (−39% to 49%), respectively. Conclusions The split-influenza vaccine was effective in preventing influenza-associated hospitalizations in adults aged under 65. The intradermal vaccine was moderately effective in those aged 65 and over.

Introduction: In 2009, two cases of seizures in adolescents following quadrivalent human papillomavirus vaccine (qHPV) administration generated important media attention, and adversely affected public trust in this vaccine. Our objectives were to describe suspected adverse reactions (SARs) reported to the Pharmacovigilance Centre in the Valencian Community (PCVC) after administration of HPV vaccine, and to compare reporting rates of syncope and seizures following this vaccine with those of other vaccines administered to girls aged 13–15 years. Materials and methods: Descriptive study of SARs reported following administration of this vaccine to the PCVC between 2007 and 2011. Results: The clinical symptoms most frequently reported were dizziness, headache, and syncope.Reporting rates of syncope or loss of consciousness and seizures with qHPV vaccine were 17 and 3.2 per 100,000 doses administered, respectively, and 15 and 1.6 for syncope or loss of consciousness and syncopal seizures occurred on the day of vaccination. The reporting rates of syncope or loss of consciousness and seizures were 6.4 and 0.4, for the other vaccines. Conclusions: Consistent with the media attention generated, and with results from other studies, the reporting rates of syncope or loss of consciousness and seizures were higher for the HPV vaccine than for other vaccines given in adolescence. Nevertheless, the overall information obtained on SARs following the qHPV vaccine suggests a good safety profile. Resumen: Introducción: En 2009, 2 casos de convulsiones en adolescentes tras la administración de la vacuna tetravalente frente al virus del papiloma humano (VPH) generaron impacto mediático y afectaron negativamente la confianza del público en esta vacuna.Nuestros objetivos fueron describir las sospechas de reacciones adversas (SRA) notificadas al Centro Autonómico de Farmacovigilancia de la Comunidad Valenciana (CAFCV) tras la administración de la vacuna frente al VPH y comparar la tasa de notificación de síncope y convulsiones de esta vacuna con la de otras vacunas administradas en adolescentes. Material y métodos: Estudio descriptivo de las notificaciones de SRA relacionadas con esta vacuna recibidas por el CAFCV entre 2007 y 2011. Resultados: Las manifestaciones clínicas más comunicadas fueron mareos, cefalea y síncope.Las tasas de notificación de síncope o pérdida de conciencia y convulsiones con la vacuna frente al VPH fueron de 17 y 3,2 por 100.000 dosis administradas, respectivamente, y de 15 y 1,6 para síncope o pérdida de conciencia y convulsiones sincopales ocurridas el día de la vacunación. Las tasas de notificación de síncope o pérdida de conciencia y convulsiones fueron de 6,4 y 0,4 para otras vacunas. Conclusiones: Las tasas de notificación de síncope o pérdida de conciencia y convulsiones fueron mayores para la vacuna frente al VPH que para otras vacunas administradas en adolescentes; esto es consistente con la atención mediática originada por la vacuna y con hallazgos de estudios previos. No obstante, la información obtenida sobre las SRA a la vacuna sugiere un buen perfil de seguridad.